Same issue for me. Since a few days no weather with xEnviro.
I tried all options suggested in this thread.
Removing the .prf file and typing in my registration data again does not get it out of activation mode. So I restored the original xenviro.prf and now it shows in the "about" that I am registered including my serial. Still no weather.
Tried to install using the exe file - no success - still no weather.
Tried to create a ticket and registered myself on the support page. Its stating it did send an email but non was received (Checked all folders including junk and spam).
I tried to login anyway but it states "account confirmation required". Without I cannot create a ticket though.